The brake shoes and the parts necessary for their operation in brake devices of this type are arranged in the space which is defined by the brake drum which rotates with the wheel on one side and the mud guard on the vehicle which is stationary in relation to the wheel. To protect these parts, attempts have been made to provide a maximum tight sealing between the wheel-sided brake drum and the vehicle-sided mud guard as a protection of the parts against contaminants and spray water.
German patent application No. 38 24 917 discloses various embodiments of a labyrinth-type sealing which are all based on the fact that an annular web is welded to the mud guard. This type of manufacture is not only comparatively expensive because the mud guard and the annular web must be joined in a special working step, it also involves major shortcomings with regard to manufacture. This is because the mud guard, which frequently has a rather complicated shape, and the annular web inhere inner tensions caused in mechanical working operations. The tensions are diminished to an uncontrollable extent in heating, which is inevitable during welding processes, and cause deformations of the component parts. Therefore, prior art mud guards with an annular web welded thereto regularly necessitate finishing operations in order to maintain the predetermined close manufacturing tolerances and to prevent rejecting a large quantity of parts as useless. Thus, the prior art mud guards necessitate a very complicated manufacture due to the required welding operation, on the one hand, and the resulting testing and finishing process steps, on the other hand.
An object of the present invention is to disclose a brake device of the above-mentioned type which, in comparison, permits manufacture at considerably lower costs and obviates the need for costly testing and finishing operations, in particular in the manufacture of mud guards.
According to the present invention, this object is achieved in that the mud guard is made of a sheet-metal part in punching and deepdrawing operations, and in that the circumferential web is integrally designed with the mud guard by noncutting shaping. The reason for this is that when the annular web in manufacture directly from the sheet-metal portion for the mud guard, the welding operation with all mentioned shortcomings will be omitted. Surprisingly, it has shown that this object can be achieved by making use of the presently available noncutting shaping techniques and that a mud guard may thus be provided, wherein the annular web is designed integrally with the other parts of the mud guard. A ready-to-mount mud guard is provided at the end of the shaping operations which does not require finishing. The shaping of the annular web can be brought into line with the shaping required in view of other functions of the mud guard. Thus, a mud guard with an annular web can be furnished which eliminates disadvantages compared to conventional embodiments.